Clamping device



Oct. 5, 1937. v. H. DONALDSON 2,094,779

CLAMPING DEVICE v Filed Feb. 28, 1936 `rmfim Uernon h' Patented Oct. 5, 1937 UNTED STATES mijn' PATENT 2 Claims.

rIhis inventionfrel'ates to .improvements in clamping devices and' proposes a device which, although not necessarily limited to such use, can be employed to advantage in connection with the assembling of structural members, the device being available, when employed for this purpose, to hold the said members in lthe desired relation until they can be secured together permanently Yin accordance with conventional practice.

One object ofthe invention is lto'provide a device whichis available forv the clamping together o f members of varying thicknesses, it being understood that the term thickness, in this as- ,pect, connotes the distance between those faces `of the members which are engaged by the cooperating parts of the device.

A further object is to provide a device which can be applied and removed with facility and v without the aid of tools, this object contemplating a construction in which the parts are automatically self-locking as the members are clamped together. l

The invention is illustrated in the accompanyring drawing in which:

Figure 1 is a view partially in elevation and partially in sectionv of a device embodying the features of the invention, the said device being illustrated in connection with two structural members which are clamped together by it.

2-2 ofFigureVl. e

4ligure 3 is a vertical section taken along line 3-3 of Figure l. A `Figures 4, 5, and 6 are perspective views of one of the parts of the device, the said views illustrating various of the forms which the said part may take. v v

Figure '7 is a view generally similar to Figure 1 and illustrates the manner in which the parts of 40 the devicemay be permanently secured against accidental release of the members whchare clamped together. Y

Figure 8 is a section taken along line 8-8 of Figure 7. v

The device is illustrated, by way of example in vconnection with structural members I0 and I I which are to be permanently secured together in any conventionalmanner as by riveting or welding, the said members being suiliciently in- 50 4dicatedl for the purpose in view by a showing of those portions which vare engaged by the parts of the device. The device, as illustrated, includes a bolt I2 which is formed to provide a I`head I3 and a shank I4. The latter is inserted 55 through registering openings I5 which are formed Figure 2 is a horizontal section taken along line in the members I0 and II, the said bolt being of such a length that the head I3 thereof eX- tends beyond the outerface of the member I while the shank It extends beyond the outer face of the member II. The bolt I2 carries spaced discs I6 which are located at opposite sides of the head I3 and which are pivotally connected thereto by a pin I'I, the said discs, as illustrated, being formed integrally with and at one end of a lever I8. The discs I6 are similar in shape and each is formed to provide diametrically opposed cam sections I9 2&3. The peaks of the former are located at an angular distance of substantially 90 in a counter-clockwise direction from the lever I8 while the peaks of the latter are located at an angular distance of substantially 90 in the opposite direction, the said cam sections sloping downwardly from said peaks to flat zones 2l which are located diametrically opposite the lever I8.

The outer end of the shank III is formed with a series of annular grooves i2, the said series eX- tending a substantial distance toward the head I3 so that one or more of the grooves will be eX- posed when the shank is inserted through the openings I5. The grooves 22 are formed to accommodate an element 23 which, as illustrated in Figures l and 4, is tapered in the direction of its length and is formed with a central slot 24 which provides spaced legs 25. The slot '24 is slightly greater in Width than the diameter of the grooved portions of the shank, the said element tapering in thickness from the top (which is of a thickness substantially equal to the width of the grooves) toward the lower ends of the legs 25. The element 23 can, therefore, be slipped over the shank I4 at any one of the grooved portions, the legs of the element straddling the reduced portion of the said shank as best shown in Figure 3.

In the use of the device the shank I4 is inserted through the openings Iii, the lever I8 being held so that it forms an extension of the shank I4. As the latter is inserted through the said openings, therefore, the flat zones 2| of the discs I6 can be moved close to or against the outer face of the member I0. The outer end of the shank extends beyond the outer face of the member II and hence one or more of the grooves 22 are accessible. The wedge 23 is then moved close to the outer wall of the member II and slipped over the shank It, the legs 25 being directed into the nearest groove. Thereafter the lever I8 is moved either in a clockwise or a counter-clockwise direction. If it is moved in the latter direction, the cam sections I9 engage the outer face of the member Ill and move'the said member toward the member II (assuming that there isa space between the time). When the lever I8 is moved to, or slightly beyond, a position in which the peak portions of the cam sections I 9 engage the outer face of the member I0, and the element 23 is correctly adjusted so that the members I9 and I I are clamped tightly against one another, the parts are self-locking, that is to say they will remain in the position'to which they are adjusted (see full-line position in Figure 1). If, however, the

Y elevation of the camV sections I9 with respect to CIK the flat zones 2I of the discs is such that the lever I8 cannot be moved toits self-locking position the element V23 is adjusted in the groove to permit the shank I4 to be partially withdrawn Yfrom the openings I5, the adjustment 'of the element being by trial anderror and being con-V tinued until a position is reached which will enable the members I and I I to' be clamped together as described. Y If the element 23 cannot be adjusted in the groove to `a position which will enable the lever to be moved to its self-locking position it is inserted in a groove more remote from the head I3 and adjusted in theslatter until the clamping together of the members IIJ Y and II and the movementof the lever I8 to a self-locking position are concurrent, the operations described being repeated, if necessary, until the proper groove is selected. On the other hand, if the members I0 and II cannot be clamped tightly together when the element 23 .is initially inserted in one of the grooves 22 and the lever I8 is moved to a self-lockingV position and if this Vcannot be effected by theV adjustment of the element in the particular groove, the said element is inserted in a groove Ycloser to the head I3 and is thereafter adjusted in the latter as described. It will be apparent, therefore, that the grooves V22 provide for initial adjustments of aV relatively large magnitude while the tapered legs of the element 23 provide for the final fine adjustment,rit being obvious that after the proper groove has been selected the iinal' fine adjustments can be readily made, for example, by performingthe following operations in the order named: (l) adjust the element 23 toV a position which will enable the lever I8.to beV movedto its self-locking position with the peak portions of the cam sections I9 abutting the outer'face of the member Ill, (2) adjust the element in the groove until it fits tightly between the outer face of the member II and the opposite wall of the groove, (3) move Vthe Vlever I8 away from the self-locking position and force the element further over the shank Il! to move the head I3 slightly toward the outer face of the memberV II), (4) and then return the lever I8 to its self-locking position. During this final movement of the said lever the members I0 and II will be forced tightly against one another. The construction described has the advantage that the pressure which the parts are caused to exert upon the said members can be varied in accordance with the requirements of the particular assembling operations.

When the lever I8 is moved in a clockwise direction the cam sections 2D are utilized, the said cam sections co-operating with the outer face of the member I0 in substantially the same manner as the cam sections I9. The peak portions of the cam sections 20 engage the member I8 when the lever I8 is moved to, or slightly beyond, anranguthe said members at peak portions of the cam-sections I9, although the relative elevations may be varied if desired. The construction described has thev advantage that the lever I8 is movable to either of two self-V locking positions (each of which corresponds .to

a different cam elevation) after each adjustment o f the element 23. The number of such adjustments which may be necessary to clamp the members I0 and II together in the manner described, is, therefore, substantially reduced.

' In order that the lever I8 may be permanently i secured in its self-locking positions, as well as in other positions, the discs I6 are formed with holes V26 'which are located equidistant from the axis of the pin II'and which can be moved to register with a hole 2l formed in the head I3 (Figure 8), certain ofthe holes 2B registering with the hole 27v during movement of the lever I 8 to utilize the cam sections I9 and other of the holes 26 registering with the hole 2'I when the cam sections 20 are employed'. The lever maybe secured in any position in which the holes 26 register with the hole 2l by a bolt 28 or other suitable fastening means. It will be apparent, therefore, that the lever I 8v can be permanently secured in either of its selflocking positions as well las in adjacent positions in which portions of the cam sections I9 and 20, other Vthan the peak portions, are utilized in clamping the members I0 and II together. Modified forms of the element 23 are shown in Figures and 6; The legs of the element shown in the latter ligure are of a uniform thickness throughout their length and hence are not available for fine adjustments in the position of the bolt I2.V This type of element, however, is preferable when the thicknesses of the members I0 and I I are uniform and predeterminedV and when the only adjustments necessary are provided by the grooves in Vthe shank I4. In the embodiment shown in Figure 5 the legs of the element 23 are stepped to provide sections 29 which increase progressively Yin thickness from the open end of the slot toward the closed end, the element in this case being movable in each groove'to provide a predetermined series of-adjustments.

I claim as my invention:

1. A device ofthe character described including a bolt which is of a length greater than the width extends beyond the opposite sides of said members, one end of said bolt being formed to provide a shoulder, an element which'ts over said bolt between said shoulder and one of said members, a cam carried by the opposite end of said bolt, said cam having peak portions of relatively different elevations, each of which is co-operative with the other of said members and a lever for-moving said cam to utilize either of said peak portions t0 Yforce said members together, said cam being mov- Y able to a self-locking position as said members are clamped together by either of said peak portions.

2. A device of the character described including a bolt which is of a length greater than the width of the members to be clamped together and which extends beyond the opposite sides of said members, one end of said bolt being formed to provide a shoulder, an element which ts over said bolt between said shoulder and one of said members, a cam carried by the opposite end of said bolt, said cam having peak portions of relatively different elevations, each of which is co-operative with the other of said members and a lever for moving said cam to utilize either of said peak portions to force said members together, said cam being movable to a self-locking position as said members are clamped together by either of said peak portions, said element varying in thickness in the direction of its length and being adjustable in such direction, whereby to enable use of the device in connection with members of different thicknesses.

VERNON H. DONALDSON. 

